Method for detecting internal plastic of living body

Abstract

The invention provides a method for detecting nano-plastics in an organism. The method comprises the following steps: exposing a to-be-detected organism by taking pre-prepared nano-plastics loaded with metal elements as an exposure material; performing homogenization treatment on each tissue of the exposed organism to be detected to obtain tissue homogenate of each tissue; respectively adding an alkaline digestion agent into the tissue homogenate of each tissue; and respectively measuring the digested tissue homogenate of each tissue in a single-particle mode of an inductively coupled plasma mass spectrometer to obtain quantitative and traced detection results of the in-vivo nano plastic of the living body to be detected. According to the method, the to-be-detected organism is exposed by using the metal-loaded nano-plastic, then the tissues of the organism are analyzed one by one, the detection quantitative results of the nano-plastic in the tissues are obtained, the migration process of the nano-plastic in the organism can be deduced according to the physiological relationship between the tissues, and the tracing detection result is obtained.

Description

Technical Field

[0001] The present invention relates to the field of detection, and in particular to a method for detecting nanoplastics in organisms. Background Art

[0002] Nanoplastics, generally referring to plastic particles smaller than 1 μm in size, are a widespread emerging pollutant in the environment. Microplastics (1 μm - 5 mm) were first discovered in the ocean in 2004. Nanoplastics primarily originate from the further degradation of microplastics or direct release from anthropogenic production activities, such as cosmetic microbeads. Based on their source, nanoplastics are categorized as primary nanoplastics (directly entering the environment at a microscopic size) and secondary nanoplastics (formed from the degradation of macroplastics). Nanoplastics possess unique physical and chemical properties at the nanoscale, such as high surface area and strong penetrability, allowing them to more easily cross biological barriers, resulting in increased bioavailability and potential harm.

[0003] Nanoplastics have been widely detected in a variety of environmental media around the world, showing the ability to migrate across media and regions. Therefore, research on the migration and distribution of nanoplastics in biological matrices will help us understand the environmental behavior and biological toxicity mechanisms of nanoplastics, and more accurate methods are also needed to detect the migration and distribution of nanoplastics. Summary of the Invention

[0004] In view of this, in order to at least partially solve at least one of the above-mentioned technical problems, the present invention provides a method for detecting nanoplastics in organisms.

[0005] According to an embodiment of one aspect of the present invention, a method for detecting nanoplastics in a living organism is provided, comprising:

[0006] The pre-prepared nanoplastic loaded with metal elements is used as the exposure material to expose the test organism;

[0007] homogenizing each tissue of the exposed organism to be tested to obtain a tissue homogenate of each tissue;

[0008] Alkaline digestion agents were added to the homogenates of each tissue;

[0009] The tissue homogenates of each digested tissue were measured in single particle mode of inductively coupled plasma mass spectrometry to obtain quantitative and tracer detection results of nanoplastics in the tested organism.

[0010] According to an embodiment of the present invention, the exposure methods include environmental exposure, food exposure, and food chain transmission.

[0011] According to an embodiment of the present invention, the alkaline digester is tetramethylammonium hydroxide.

[0012] According to an embodiment of the present invention, the concentration of the alkaline digester is 25% to 50%.

[0013] According to an embodiment of the present invention, the digestion time is 6-12 hours, and the digestion temperature is 20-30°C.

[0014] According to an embodiment of the present invention, the metal element includes at least one of neodymium, terbium, gold, silver, iron, copper, and europium.

[0015] According to an embodiment of the present invention, the nanoplastic loaded with metal elements is europium chelate-labeled polystyrene nanoplastic particles.

[0016] According to an embodiment of the present invention, the nanoplastic loaded with metal elements is prepared by a swelling-diffusion method.

[0017] According to an embodiment of the present invention, the quantitative detection results include the particle concentration of nanoplastics in various tissues;

[0018] The tracer detection results include the migration and distribution results of nanoplastics in the tested organism, wherein the migration and distribution results are determined based on the particle concentration of nanoplastics in each tissue and the anatomical information of the organism's tissue.

[0019] According to an embodiment of the present invention, the europium chelate is Eu(TTA)3.

[0020] According to an embodiment of the present invention, by utilizing metal-loaded nanoplastics, the organism to be tested is exposed, and then each tissue of the organism is analyzed one by one to obtain the quantitative detection results of the nanoplastics in each tissue, and then the migration process of the nanoplastics in the organism can be inferred based on the physiological relationship between the tissues, and the tracer detection results are obtained; specifically, by utilizing alkaline digesters, biological matrices such as proteins and lipids can be gently dissolved, while avoiding acid digestion to corrode metal markers or damage to the nanoplastic structure, and the signal of the loaded metal is significantly distinguished from the background metal interference in the organism, reducing the background interference in the detection process, and then by using the single particle mode of the inductively coupled plasma mass spectrometer for measurement, the metal signals of the nanoplastic particles can be detected one by one, and combined with time-resolved analysis, the direct counting of the nanoplastic particle concentration can be achieved, thereby obtaining the detection results and improving the detection sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0022] Figure 1 This is a schematic flow chart of a method for detecting nanoplastics in living organisms according to an embodiment of the present invention;

[0023] Figure 2This is a schematic diagram of the quantitative determination process of the migration and distribution of nanoplastics in different tissues of zebrafish under environmental exposure using europium chelate-labeled polystyrene nanoplastic particles according to an embodiment of the present invention;

[0024] Figure 3 Figures 1 and 2 are the characterization results of europium chelate-labeled polystyrene nanoplastic particles according to an embodiment of the present invention, with a-b being scanning electron microscopy (SEM) images, c-h being transmission electron microscopy (TEM) images, and i-j being signal graphs of single-particle inductively coupled plasma mass spectrometry.

[0025] Figure 4 Comparison diagram of polystyrene nanoplastics synthesized in an embodiment of the present invention before and after digestion, a~b are scanning electron microscopy images, c~d are single particle inductively coupled plasma mass spectrometry signal diagrams, and e is a schematic diagram of the free rate of europium chelates in different tissue components;

[0026] Figure 5 This is a performance curve of the method for detecting multiple tissues of zebrafish using metal-loaded nanoplastic particles according to an embodiment of the present invention;

[0027] Figure 6 This is a statistical graph showing the recovery rates of multiple zebrafish tissues detected in an embodiment of the present invention;

[0028] Figure 7 This is a diagram showing the detection results of chelate-labeled polystyrene nanoplastic particles in different zebrafish tissues according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.

[0030] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The term "comprising" used herein indicates the existence of features, steps, operations, but does not exclude the existence or addition of one or more other features.

[0031] When expressions such as “at least one of A, B, and C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, “a system having at least one of A, B, and C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.). When expressions such as “at least one of A, B, or C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, “a system having at least one of A, B, or C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.).

[0032] During the process of realizing the concept of the present invention, it was discovered that the ocean is the main gathering area for nanoplastics, with an annual input of hundreds of millions of tons, and it is widely present in ecologically sensitive areas such as deep-sea sediments and coral reefs. In the terrestrial environment, agricultural soil has become an important pollution area for nanoplastics due to the weathering of plastic films. Industrial activities in the urban atmosphere, such as plastic processing and municipal engineering, are the main pathways for the gaseous diffusion of nanoplastics. It is worth noting that nanoplastics can migrate to remote areas such as the polar regions and high mountains through atmospheric circulation and other pathways, and even form long-term deposits in glaciers and snow samples, confirming their global diffusion potential. In biological media, nanoplastics are enriched in fish, crops, and human tissues (such as blood and placenta) through ingestion, respiration, and other pathways, highlighting their risk of transmission through the food chain. The enrichment of nanoplastics in biological matrices causes biological toxicity, can penetrate biological barriers and cause direct damage, and are also prone to adsorb heavy metals, persistent pollutants, etc. to form complex toxicity. At the same time, they can also accumulate in higher trophic level organisms through the food chain and enter the human body through respiratory and dietary routes, penetrating the alveoli, blood-brain barrier, and even the placenta, causing cell damage, abnormal immune responses, and potential developmental toxicity, posing multiple threats to human health. Therefore, studying the migration and distribution of nanoplastics in biological matrices helps to understand the environmental behavior and biological toxicity mechanisms of nanoplastics.

[0033] However, the quantitative analysis and tracing of nanoplastics currently face multiple challenges. Traditional spectroscopic techniques (such as FTIR and Raman) are insufficiently capable of identifying nanoscale particles, and electron microscopy techniques struggle to achieve in situ analysis in complex matrices. Organic components in biological samples can easily mask nanoplastic signals, and the recovery rates of different extraction methods (such as enzymatic hydrolysis and centrifugation) vary significantly, affecting data comparability. Emerging technologies such as single-particle inductively coupled plasma mass spectrometry (sp-ICP-MS) combined with metal probe labeling have improved detection limits but are still limited by the sensitivity of carbon-based materials, and their application to biological tissues requires method standardization.

[0034] Figure 1Schematic diagram of the process of detecting nanoplastics in organisms according to an embodiment of the present invention.

[0035] Specifically, according to an embodiment of one aspect of the present invention, a method for detecting nanoplastics in a living body is provided, such as Figure 1 As shown, it includes steps S1 to S4:

[0036] Step S1: exposing the organism to be tested using a pre-prepared nanoplastic loaded with metal elements as an exposure material;

[0037] Step S2: homogenizing the exposed tissues of the test organism to obtain tissue homogenates of the tissues;

[0038] Step S3: adding alkaline digestion agents to the homogenates of each tissue;

[0039] Step S4: The tissue homogenates of each digested tissue are measured separately by the single particle mode of inductively coupled plasma mass spectrometry (sp-ICP-MS) to obtain quantitative and tracer detection results of nanoplastics in the tested organism.

[0040] According to an embodiment of the present invention, by utilizing metal-loaded nanoplastics, the organism to be tested is exposed, and then each tissue of the organism is analyzed one by one to obtain the quantitative detection results of the nanoplastics in each tissue, and then the migration process of the nanoplastics in the organism can be inferred based on the physiological relationship between the tissues, and the tracer detection results are obtained; specifically, by utilizing alkaline digesters, biological matrices such as proteins and lipids can be gently dissolved, while avoiding acid digestion to corrode metal markers or damage to the nanoplastic structure, and the signal of the loaded metal is significantly distinguished from the background metal interference in the organism, reducing the background interference in the detection process, and then by using the single particle mode of the inductively coupled plasma mass spectrometer for measurement, the metal signals of the nanoplastic particles can be detected one by one, and combined with time-resolved analysis, the direct counting of the nanoplastic particle concentration can be achieved, thereby obtaining the detection results and improving the detection sensitivity.

[0041] According to an embodiment of the present invention, the exposure methods include environmental exposure, food exposure, and food chain transmission.

[0042] According to the embodiments of the present invention, actual exposure patterns in natural environments are simulated through multiple exposure pathways such as direct contact with aquatic environments, ingestion of contaminated food, and predation of organisms containing nanoplastics, so that the detection results are closer to the needs of real ecotoxicity research. For example, food chain transmission experiments can reveal the cross-species enrichment patterns of nanoplastics in organisms, filling the limitations of traditional single exposure methods.

[0043] According to an embodiment of the present invention, the alkaline digestion agent is tetramethylammonium hydroxide (TMAH).

[0044] According to an embodiment of the present invention, the strong alkalinity of TMAH (pH 12-14) can quickly dissolve biological tissues such as proteins and lipids, while avoiding the destruction of the nanoplastic structure or the dissociation of metal chelates by acid digestion. At the same time, the solution after TMAH digestion has low viscosity and uniformly dispersed particles, reducing the risk of clogging of the mass spectrometry injection system and ensuring the stability of single-particle signals. In addition, TMAH does not contain high background metal impurities (such as K and Na, which have high content in NaOH), reducing the background noise of mass spectrometry detection and improving the detection sensitivity of trace nanoplastics.

[0045] According to an embodiment of the present invention, the concentration of the alkaline digester is 25% to 50%.

[0046] According to an embodiment of the present invention, the concentration of the alkaline digester can be 25%, 30%, 35%, 40%, 45%, or 50%, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0047] According to an embodiment of the present invention, TMAH in a concentration range of 25%-50% can fully dissolve biological tissue under mild conditions, while avoiding incomplete digestion caused by too low a concentration or swelling and deformation of nanoplastics caused by too high a concentration.

[0048] According to an embodiment of the present invention, the digestion time is 6-12 hours, and the digestion temperature is 20-30°C.

[0049] According to an embodiment of the present invention, the digestion time can be 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, or 12 hours, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable. The digestion temperature can be 20°C, 22°C, 24°C, 26°C, 28°C, or 30°C, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0050] According to an embodiment of the present invention, an appropriate digestion time can completely dissolve the biological matrix while avoiding the slow dissociation of metal markers due to excessive time; an appropriate digestion temperature can prevent high temperature from accelerating the degradation of nanoplastics or the decomposition of metal chelates, ensuring the integrity of the particle morphology and avoiding the unreality of subsequent test results.

[0051] According to an embodiment of the present invention, the metal element includes at least one of neodymium, terbium, gold, silver, iron, copper, and europium.

[0052] According to an embodiment of the present invention, rare earth elements (neodymium, terbium, and europium) have unique mass spectrometry signals such as high-abundance isotopes, which reduce biological background interference; precious metals (gold and silver) are chemically inert and do not easily react with environmental substances after labeling, making them suitable for long-term tracing experiments.

[0053] In some specific embodiments of the present invention, a multi-element labeling strategy can be adopted to achieve multi-target simultaneous detection by labeling nanoplastics of different particle sizes / types with different metals.

[0054] According to an embodiment of the present invention, the nanoplastic loaded with metal elements is europium chelate-labeled polystyrene nanoplastic particles.

[0055] According to an embodiment of the present invention, the europium chelate is Eu(TTA)3.

[0056] According to embodiments of the present invention, europium (Eu) exhibits high signal intensity (low background interference) in mass spectrometry. Due to its extremely high sensitivity and extremely low environmental background concentration in inductively coupled plasma mass spectrometry, europium is an ideal choice for labeling nanoplastics in the present invention. In particular, the Eu(TTA)3 chelate exhibits excellent stability under alkaline conditions. Hydrophobic polystyrene and the hydrophobic chelate Eu(TTA)3 are highly compatible, and the swelling-diffusion method allows for uniform metal loading, achieving labeling efficiencies exceeding 95%.

[0057] According to an embodiment of the present invention, the nanoplastic loaded with metal elements is prepared by a swelling-diffusion method.

[0058] According to an embodiment of the present invention, the swelling-diffusion method utilizes an organic solvent (such as THF) to swell polystyrene particles, allowing the metal chelate to diffuse into the interior. This method can achieve a high loading rate. Simultaneously, internal labeling of the particles reduces exposure of the metal to the external environment, reducing label loss during transportation or exposure. Furthermore, by adjusting parameters such as swelling time and solvent ratio, the metal loading and particle size can be precisely controlled, thereby improving the sensitivity of subsequent detection. Specifically, the hydrophobic interaction between the chelate and the polystyrene nanoplastic ensures the stability of the label. This method can achieve sufficient europium loading to meet the detection requirements of single-particle inductively coupled plasma-mass spectrometry.

[0059] According to an embodiment of the present invention, the quantitative detection results include the particle concentration of nanoplastics in various tissues;

[0060] The tracer detection results include the migration and distribution results of nanoplastics in the tested organism, wherein the migration and distribution results are determined based on the particle concentration of nanoplastics in each tissue and the anatomical information of the organism's tissue.

[0061] According to an embodiment of the present invention, the absolute value can be directly obtained by sp-ICP-MS single particle counting, avoiding the errors of traditional semi-quantitative methods such as fluorescence intensity. Then, combined with tissue anatomy such as intestinal absorption rate and blood-brain barrier permeability, a dynamic migration model of nanoplastics is constructed, so that the toxic effects can be correlated according to the distribution data, providing direct evidence for nanoplastic risk assessment.

[0062] The methods in the following examples are conventional methods unless otherwise specified, and the reagents and raw materials used can be obtained from public commercial channels unless otherwise specified.

[0063] Example 1 Synthesis of Europium Chelate Labeled Polystyrene Nanoplastic Particles

[0064] Figure 2 This is a schematic diagram of the quantitative determination process of the migration and distribution of nanoplastics in different tissues of zebrafish under environmental exposure using europium chelate-labeled polystyrene nanoplastic particles according to an embodiment of the present invention.

[0065] The synthesis process is as follows Figure 2 As shown, styrene (16.5 mL), acrylic acid (2.14 mL) and ultrapure water were degassed with nitrogen for 20 min. Then, 140 mL of ultrapure water was added to a glass reactor equipped with a metal stirring device (350 rpm), and the styrene and acrylic acid mixture was added thereto. After the system temperature was stabilized at 70°C using external cooling water, a pre-prepared ammonium persulfate solution (75 mg) and 10 mL of ultrapure water were added to the system. After a 10-h reaction, the mixture was cooled to room temperature. The nanoplastics dispersed in the aqueous phase were then centrifuged at 12,000 rpm for 30 min, and this was repeated 5 to 6 times to purify the polystyrene nanoplastics. Among them, ammonium persulfate was used as an initiator to synthesize surfactant-free and metal-catalyst-free polystyrene nanoplastics through soap-free copolymerization to reduce detection interference.

[0066] Add 2 mmol of europium trichloride (20 mL) to a 30 mL ethanol solution containing 6 mmol of 2-thenoyltrifluoroacetone (TTA). Adjust the pH of the solution to 7.0 using 2 mol / L sodium hydroxide. Heat the solution to 60°C with magnetic stirring, and precipitation will be observed. The mixture is then stirred at 60°C for 1 hour. Finally, the europium chelate (Eu(TTA)3) is collected by filtration, washed with ultrapure water, and dried at 70°C overnight.

[0067] The europium chelate was dissolved in 30 mL of methanol as the first solution. The second solution (containing 100 mL of polystyrene nanoplastic) was then added to acetone as an expansion agent. The pH of the solution was adjusted to 7.0 using 2 mol / L sodium hydroxide. The first solution was heated to 90°C under magnetic stirring and then added to the second solution. After stirring for 40 min, the mixture was slowly cooled to room temperature. The solution obtained above was then filtered through a glass fiber filter membrane to obtain europium chelate-labeled polystyrene nanoplastic particles. The europium chelate-labeled polystyrene nanoplastic particles were characterized, and the results were as shown below. Figure 3 shown

[0068] Figure 3These are the characterization results of europium chelate-labeled polystyrene nanoplastic particles in an embodiment of the present invention, a~b are scanning electron microscopy (SEM) images, c~h are transmission electron microscopy (TEM) images, and i~j are signal diagram results of single particle inductively coupled plasma mass spectrometry.

[0069] according to Figure 3 It can be seen that the appearance and shape of the prepared polystyrene nanoplastic particles have not changed significantly under the characterization of SEM and TEM techniques. At the same time, the distribution of europium and related chelate elements such as sulfur and fluorine coincides well with the plastic particles. The europium chelate labeling efficiency is good and will not affect the appearance of the polystyrene nanoplastic. The characteristic peaks are significant in the single-particle inductively coupled plasma mass spectrometry.

[0070] Example 2 Quantitative determination of nanoplastic migration and distribution in different tissues of zebrafish under environmental exposure

[0071] Continue to refer Figure 2 Schematic diagram shown. Healthy adult zebrafish (normal feeding behavior, no body lesions, and good vitality) that had been acclimated for at least one week were selected as experimental organisms. Prior to the experiment, the selected individuals were fasted for 12 hours to eliminate interference from digestive tract residues.

[0072] In the zebrafish exposure experiment, the living conditions of the fish were kept the same as during acclimation. The experiment set up an experimental group and a control group. The exposure environment volume of each group was 3 L, with a total of 40 zebrafish. The experimental group was added with the polystyrene nanoplastic suspension synthesized in Example 1, and the particle concentration was set to 2.5×10 10 particles / L (the final measured concentration was maintained at 2.01×10 10 particle / L, which is 2.01×10 4 particles / mg).

[0073] The control group received the same volume of ultrapure water, and all other environmental parameters remained the same. The exposure period was 7 days, with daily feeding and three biological replicates (n=3), each containing one zebrafish.

[0074] After exposure, each zebrafish was thoroughly rinsed several times with ultrapure water before dissection to remove any nanoplastics potentially adsorbed on the fish's surface. The zebrafish brain, viscera, intestine, and egg tissues were dissected and weighed, and the tissue mass was recorded. A homogenizer was used to prepare a tissue homogenate. 1 mL of the homogenate was placed in a centrifuge tube and 1 mL of 25% tetramethylammonium hydroxide was added. The mixture was shaken on a shaker for 10 minutes to thoroughly mix. The mixture was then allowed to stand at 25°C for 12 hours to fully digest the tissue components and obtain a clear solution. The digested nanoplastics were then characterized, as shown in the following results. Figure 4 shown.

[0075] Take 1 mL of the above clear solution and add it to 9 mL of ultrapure water, dilute it 10 times, and then measure the sample in the single particle mode of inductively coupled plasma mass spectrometry without additional treatment. The sample is placed on the automatic sampler of the inductively coupled plasma mass spectrometer for measurement. The specific parameter settings are shown in Table 2. The concentration of nanoplastic particles in different tissue components is obtained. The results are shown in Tables 1 and 2. Figure 5 、 Figure 6 and Figure 7 shown.

[0076] Table 1

[0077]

[0078] Figure 4 These are comparison diagrams of the polystyrene nanoplastic synthesized in an embodiment of the present invention before and after digestion, a~b are scanning electron microscope images, c~d are single particle inductively coupled plasma mass spectrometry signal diagrams, and e is a schematic diagram of the free rate of europium chelates in different tissue components.

[0079] according to Figure 4 It can be seen that under the set digestion temperature and time conditions, the biological components can be effectively digested and a good nanoplastic detection recovery rate can be obtained. This digestion method will not affect the quantitative determination of polystyrene nanoplastics while removing the background interference of biological tissues. The content of europium chelate in the solution is relatively low, indicating that the loading effect is stable.

[0080] Figure 5 This is a performance curve of the method for detecting multiple tissues of zebrafish using metal-loaded nanoplastic particles in an embodiment of the present invention.

[0081] according to Figure 5 As can be seen from Table 1, which shows the performance and validation of the assay in four tissues: zebrafish brain, viscera, intestine, and egg tissues, the relative standard deviation (RSD) of different groups ranged from 2.86% to 7.96%, indicating that the method has good reproducibility. The present invention was used to measure the particle concentration and obtain the recovery rate by adding the same concentration gradient of polystyrene nanoplastics to the four tissues: zebrafish brain, viscera, intestine, and egg tissues, as well as ultrapure water (as a control group). All experimental groups were within the range of 0.8-40×10 9 particle / L (i.e. 0.8 - 40×10 3 particles / mg) showed excellent linear correlation (R 2> 0.98). Furthermore, the linear fit curves for the four groups showed high consistency, indicating negligible matrix interference under the current pretreatment conditions. Furthermore, the intercept values ​​for all groups were consistently close to zero, further confirming the negligibility of matrix effects and instrumental systematic errors. The relative standard deviations (RSDs) for the different groups ranged from 2.86% to 7.96%, demonstrating good reproducibility of the method.

[0082] Figure 6 This is a statistical graph of the recovery rates of multiple zebrafish tissues detected in an embodiment of the present invention.

[0083] according to Figure 6 It can be seen that the zebrafish brain, viscera, intestine and egg tissues and ultrapure water (as a control group) spiked with polystyrene nanoplastic (1.68×10 9 particles / L, which is 1.68×10 3 The particle concentration was measured using the present invention, and the recovery rate was greater than 89.4%.

[0084] Figure 7 This is a diagram showing the detection results of chelate-labeled polystyrene nanoplastic particles in different zebrafish tissues according to an embodiment of the present invention.

[0085] according to Figure 7 It can be seen that the concentration of polystyrene nanoplastic particles in intestinal tissue reached 3.04×10 5 particle / mg, accounting for 89.9%, and the particle concentration in visceral tissues reached 1.07×10 5 particle / mg, accounting for 5.42%, and the particle concentration in brain tissue reached 2.14×10 4 particle / mg, accounting for 4.05%, while the particles in egg tissue are only 5.51×10 2 particle / mg, accounting for 0.55%. It is proved that the intestine is the main distribution area of ​​polystyrene nanoplastics in zebrafish. At the same time, it will migrate to the internal organs and brain tissues through the blood circulation system, while the egg tissue is basically unaffected by polystyrene nanoplastics. This shows that this method can accurately quantify the particle concentration of nanoplastics in biological matrices under environmental exposure conditions and realize the migration and distribution study of nanoplastics in organisms. The detection limit of polystyrene nanoplastics in biological matrices by the method of the present invention is 8.0×10 2 particle / mg.

[0086] Table 2 shows the method parameters of single particle inductively coupled plasma mass spectrometry used in Example 2 of the present invention.

[0087] Table 2

[0088]

[0089] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for detecting nanoplastics in a living organism, comprising: The pre-prepared nanoplastic loaded with metal elements is used as the exposure material to expose the test organism; homogenizing each tissue of the exposed organism to be tested to obtain a tissue homogenate of each tissue; adding alkaline digestion agents to the tissue homogenates of the respective tissues; The tissue homogenates of the digested tissues are respectively measured in single particle mode of an inductively coupled plasma mass spectrometer to obtain quantitative and tracer detection results of nanoplastics in the tested organism.

2. The detection method according to claim 1, wherein The exposure modes include environmental exposure, food exposure, and food chain transmission.

3. The detection method according to claim 1, wherein The alkaline digester is tetramethylammonium hydroxide.

4. The detection method according to claim 1 or 3, wherein The concentration of the alkaline digester is 25% to 50%.

5. The detection method according to claim 1 or 3, wherein The digestion time is 6~12h, and the digestion temperature is 20~30℃.

6. The detection method according to claim 1, wherein The metal element includes at least one of neodymium, terbium, gold, silver, iron, copper, and europium.

7. The detection method according to claim 1 or 6, wherein The metal element-loaded nanoplastic is europium chelate-labeled polystyrene nanoplastic particles.

8. The detection method according to claim 1, wherein The metal element-loaded nanoplastic is prepared by a swelling-diffusion method.

9. The detection method according to claim 1, wherein The quantitative detection results include the concentration of nanoplastic particles in various tissues; The tracer detection result includes the migration and distribution result of the nanoplastic in the organism to be tested, wherein the migration and distribution result is determined based on the particle concentration of the nanoplastic in each tissue and the anatomical information of the organism tissue.

10. The detection method according to claim 1 or 6, wherein The europium chelate is Eu(TTA)3.

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